The disclosure relates to refrigeration. More particularly, the disclosure relates to economized chiller systems.
A typical chiller system comprises a vapor compression refrigeration system having a compressor, a condenser, and an evaporator along a recirculating refrigeration flowpath. An expansion device is between condenser and evaporator. Exemplary condensers and evaporators are refrigerant-water heat exchangers so that refrigerant compressed by the compressor is cooled in the condenser by transferring heat to a first water loop. Refrigerant is further cooled by expansion in the expansion device and absorbs heat in the evaporator from a second water loop.
An economizer may be added to the system to reduce the vapor percentage of refrigerant delivered to the evaporator, thereby increasing the latent heat of refrigerant delivered to the evaporator. An exemplary economizer is a flash tank economizer wherein a portion of the refrigerant delivered from the condenser is expanded (flashed) into a vapor portion, leaving a liquid portion. The vaporized refrigerant is returned to an economizer port along the compressor. The expansion further cools the liquid refrigerant prior to its delivery to the primary expansion device and then the evaporator. Two exemplary economized chillers are the models 19EX and 23XRV of Carrier Corporation, Syracuse, N.Y., USA.